1. Field of The Invention
This invention is related to soil injection systems; and, one aspect, to such a system with effective control of jetted material; with efficient injection with relatively small amounts of chemical(s), in an environmentally safe manner and at relatively low, controlled pressures; and with thorough mixing of material to be injected.
1. Description of Related Art
The prior art discloses a wide variety of soil injection systems developed over many decades for injecting various substances in to soil
U.S. Pat. No. 3,815,525 discloses apparatus for intermittent injection of liquid into soil at a pulse pressure of 1000 to 3500 arm. Liquid under high pressure is injected into the root zone of plants in soil by the action of accumulated impact energy in the form of continuous pulse jets by a device for effecting injection of liquid which has a chamber adapted to accumulate the liquid and a nozzle disposed in the lower portion of the chamber and adapted to discharge liquid as pulse jets. A plunger is accommodated in the chamber, reciprocated to transmit an impact to the liquid and is connected to a resilient compression member adapted to accumulate energy.
U.S. Pat. No. 4,907,516 discloses apparatus for pulsed injection of liquid into soil at 6000 p.s.i. A pressure regulator and control unit with solenoid valve is used. Fertilizer or other liquid crop treatment is applied to the ground using a direct injection jet with a nozzle position closely adjacent the ground and forming a jet of the liquid directed into the ground. A solenoid controlled valve cyclically baits the flow of fluid to form short pulses of the fluid so that the fluid can be supplied in concentrate form while generating sufficient energy to achieve a depth of penetration in the range two to four inches. The solenoid controlled valve and nozzle is mounted on a skid member carried on a depth control wheel. The period of the pulses is arranged so that the length of a pulse is very short relative to the spacing between the pulses with the spacing between adjacent rows formed by adjacent heads being substantially equal to the spacing between the individual pulses.
U.S. Pat. No. 3,330,070 discloses injection apparatus mountable behind a tractor which includes a compressor, control valves and a reservoir maintained at a desired pressure for injecting one to two gallons per minute of petroleum based emulsions delivered at thirty to sixty p.s.i.
U.S. Pat. No. 4,970,973 discloses a field planting system which employs: accumulators, microprocessor controllers, pumps, an air compressor, and venting apparatus. The system is used to apply water, chemicals, herbicides, pesticides, and fertilizers in conjunction with planting seeds.
U.S. Pat. No. 5,101,745 discloses a system for injecting liquid into soil at 2300 to 5500 p.s.i with pulses 0.010 to 0.065 seconds apart. The system uses an accumulator and control valves and has a roller assembly for applying mechanical pressure to turf after cultivation with a means for setting a first speed in a transport mode and a second speed in a cultivating mode. The apparatus is bidirectional to allow the apparatus to be used in both a forward and reverse direction. The flow of the pressurized liquid is controlled at intervals through nozzles having diameters of from about 0.033 to about 0.090 inches. The apparatus utilizes a water hammer effect to effect the flow of pressurized liquid out of the nozzles and discloses a relationship in the pressure and pounds per square inch of the cross-sectional area of the bore of the manifold to the accumulated area of the output ports of the nozzles.
U.S. Pat. No. 4,807,544 discloses a liquid injection system with an emergency bypass valve and an air compressor and a method and apparatus for injecting agrochemicals into the subsurface of the soil without tilling of the soil. A high pressure pump delivers the solution to be injected to a series of injection nozzles. The injection nozzles cause liquid jets to be formed which have sufficient velocity and narrow cross-section to inject into the soil. The injection nozzles are supported by a shield-pan which rides on the surface of the soil. The apparatus causes continuous injection from a plurality of nozzles. The shield-pan minimizes clogging of the nozzles. A second low pressure system is incorporated to broadcast spray the soil surface utilizing a boom with broadcast nozzles.
U.S. Pat. No. 4,624,193 discloses a liquid injection apparatus for delivering liquid pulses with a high pressure metering pump. Injection pressure is maintained at 1800 to 2200 p.s.i. A nitrogen gas accumulator and a safety relief valve are used. The system has a series of jet nozzles, one for each plant row, spaced along a tool bar carried by a tractor which normally tows a nurse tank containing the liquid. A pump having an adjustable delivery rate is driven at a rate proportional to ground speed of the tractor, normally by the power take-off of the tractor, to deliver liquid from the nurse tank under substantially constant high pressure. A timing distributor, also driven by the power take-off, connects the high pressure liquid, i.e., the pump output, successively to the nozzles so that the entire output of the pump is concentrated through one nozzle at a time, for a very brief interval, to inject a high velocity slug of liquid which will penetrate the soil to an agronomically satisfactory depth. The timing is such that one slug is injected for each nozzle during a predetermined distance of travel, e.g., twelve inches, to provide a series of equally spaced injections along each plant row.
U.S. Pat. No. 5,207,168 discloses a system for reducing soil density. A metering valve, a plurality of jets, an accumulator and a suitable pressure relief valve are used to provide a lateral dispersion of the liquid within the soil such that the liquid dispersion from adjacent jets coact with one another to lift and fracture the soil. A plurality of small diameter nozzles are mounted on a movable frame generally transverse to the direction of travel of the frame. A pressurized fluid source is mounted on the frame and connected through a control device to the nozzles. The control device controls the flow of liquid from the pressure source to the nozzles to produce periodic, relatively small cross-sectional, slugs, or jets, of liquid from the nozzles through the turf into the soil. The pressure on each slug of liquid is such that the liquid penetrates through the turf into the soil and also disperses generally laterally within the soil.
U.S. Pat. No. 4,481,894 discloses a herbicide spreader with nozzles, a pump, air compressor, and reservoir for producing pulses for injection.
U.S. Pat. No. 3,012,526 discloses a liquid injection system with vent apparatus to inject agricultural chemicals into the soil from a moving vehicle by propelling elongated consolidated slugs of liquid at high velocity so that the unconfined slugs are caused to penetrate the soil while substantially intact and before breaking up to any considerable degree. The slug is propelled from an ejector device positioned in close proximity to the soil, for example, within a fraction of an inch thereof. Penetration depths of six to eight inches or more are readily achieved with pressures of 500 p.s.i. to 1500 p.s.i., depending on the condition of the soil.
U.S. Pat. No. 4,009,666 discloses apparatus for injecting a fluid below a soil or turf surface having a handle with a support rod attached thereto, and a plurality of nozzles carried by the support rod, each nozzle forming a stream of fluid passing therethrough. Each nozzle is provided with a skid having a curved surface for low friction contact with the soil or turf surface and for holding the nozzle out of contact with the surface. The apparatus is provided with a pump which cooperates with the nozzle to inject the fluid substantially below the soil surface.
U.S. Pat. No. 2,988,025 discloses a method for applying liquids into soil with liquid injected at velocities of the order of 700 to 1,100 feet per second to obtain penetration depths that are satisfactory from the point of view of agronomy, e.g., of the order of four inches or more.
U.S. Pat. No. 2,930,334 discloses apparatus for soil treatment by injecting fertilizer into soil in the form of a liquid to a depth at which the fine tendrils of roots are enabled to readily absorb the plant food for the nourishment of the plants. Weeds competing with the plants being cultivated are killed more quickly and effectively by injecting the weed killer in the form of a liquid into the ground at such depth that the roots of the weeds become quickly subjected to the destructive properties of the weed killer. This method is satisfactory for controlling plant killing grubs or insects that exist in the ground.
Certain prior art systems employ commercially available prior art sequencing control valves, but some of these systems have difficulty due to the need for manual adjustment of the valve.